The pattern-wise application of dye stuffs to textile materials involves a large quantity of digitally encoded pattern data which must be sorted and routed to a large number of individual dye jets. Typically, these systems include several arrays or gun bars comprised of individually controllable or addressable dye jets which are arranged and spaced in a parallel relation generally above and across the path of a moving web of substrate. For a given desired pattern, each gun bar is associated with a single color of dye. Each of the jets in the gun bar directs a stream of dye at the moving substrate to apply the correct pattern to the substrate. When the jet is "firing" dye is being applied to the substrate and when the jet is "not firing" no dye is dispensed.
Precise pattern resolution along the direction of the substrate travel depends primarily upon the speed and precision with which the individual dye streams can be made to strike or not strike the continuously moving substrate. A problem with the prior known dyeing devices is that the devices are limited in that the period of time during which any of the dye streams in a given gun bar are allowed to strike the substrate must be the same for all jets in the gun bar. In effect, these prior devices are incapable of allowing one jet to dispense dye onto the substrate for a different period of time than another jet in the same gun bar. This limitation is reflected in an inability to produce side-to-side shade variations simply by varying the quantity of dye applied to the substrate across the width of the given gun bar.
There is therefore needed a simple and efficient process and apparatus for individually assigning firing times to each dye jet across a gun bar.